diff --git a/test/expected/cast.out b/test/expected/cast.out
index e1042de..4824261 100644
--- a/test/expected/cast.out
+++ b/test/expected/cast.out
@@ -38,6 +38,8 @@ SELECT '{-Infinity}'::real[]::vector;
 ERROR:  infinite value not allowed in vector
 SELECT '{}'::real[]::vector;
 ERROR:  vector must have at least 1 dimension
+SELECT '{{1}}'::real[]::vector;
+ERROR:  array must be 1-D
 SELECT '[1,2,3]'::vector::real[];
  float4  
 ---------
diff --git a/test/sql/cast.sql b/test/sql/cast.sql
index cb5c880..c73ab07 100644
--- a/test/sql/cast.sql
+++ b/test/sql/cast.sql
@@ -8,6 +8,7 @@ SELECT '{NaN}'::real[]::vector;
 SELECT '{Infinity}'::real[]::vector;
 SELECT '{-Infinity}'::real[]::vector;
 SELECT '{}'::real[]::vector;
+SELECT '{{1}}'::real[]::vector;
 SELECT '[1,2,3]'::vector::real[];
 SELECT array_agg(n)::vector FROM generate_series(1, 16001) n;
 SELECT array_to_vector(array_agg(n), 16001, false) FROM generate_series(1, 16001) n;